The question is attached above together with part of the solution. Please send the value of x after solving the inequality as above.

Asked by sudhanshubhushanroy | 17th Nov, 2017, 07:40: PM

Expert Answer:

begin mathsize 16px style please space do space check space the space question space it space will space be space cosx space not space cos squared straight x
sin 2 straight x greater than cosx space considering space open square brackets 0 comma 2 straight pi close square brackets
sin 2 straight x minus cosx greater than 0
cosx left parenthesis 2 sinx minus 1 right parenthesis greater than 0
now space cosx space and space left parenthesis 2 sinx minus 1 right parenthesis space should space have space same space signs
cosx greater than 0 space & space space left parenthesis 2 sinx minus 1 right parenthesis space greater than 0 space or space cosx less than 0 space & space space left parenthesis 2 sinx minus 1 right parenthesis space less than 0
for space cosx greater than 0 space & space space left parenthesis 2 sinx minus 1 right parenthesis space greater than 0
cosx space greater than 0 space for space straight x element of open parentheses 0 comma straight pi over 2 close parentheses union open parentheses fraction numerator 3 straight pi over denominator 2 end fraction comma 2 straight pi close parentheses
sinx greater than 1 half for space straight x element of open parentheses straight pi over 4 comma fraction numerator 3 straight pi over denominator 4 end fraction close parentheses
intersection space straight x element of open parentheses straight pi over 4 comma straight pi over 2 close parentheses
similarly space for space cosx less than 0 space & space space left parenthesis 2 sinx minus 1 right parenthesis space less than 0 end style

Answered by Arun | 18th Nov, 2017, 08:57: PM